Research has demonstrated that in controlled experiments in which small groups are being tutored by researchers, reading-strategy instruction is highly effective in fostering reading comprehension (Palincsar & Brown, "Cognition and Instruction," 1(2), 117-175, 1984). It is unclear, however, whether reading-strategy interventions are equally effective in whole-classroom situations in which the teacher is the sole instructor for the whole class. This meta-analysis focuses on the effects of reading-strategy interventions in whole-classroom settings. Results of studies on the effectiveness of reading-strategy interventions in whole-classroom settings were summarized (N[subscript studies] = 52, K = 125) to determine the overall effects on reading comprehension and strategic ability. In addition, moderator effects of intervention, study, and student characteristics were explored. The analysis demonstrated a very small effect on reading comprehension (Cohen's d = 0.186) for standardized tests and a small effect (Cohen's d = 0.431) on researcher-developed reading comprehension tests. A medium overall effect was found for strategic ability (Cohen's d = 0.786). Intervention effects tended to be lower for studies that did not control for the hierarchical structure of the data (i.e. multilevel analyses). For interventions in which "setting reading goals" was part of the reading-strategy package, effects tended to be larger. In addition, effects were larger for interventions in which the trainer was the researcher as opposed to teachers and effect sizes tended to be larger for studies conducted in grades 6-8. Implications of these findings for future research and educational practice are discussed.